I. Field
The present disclosure relates generally to communication, and more specifically to techniques for sending and receiving signaling in wireless communication systems.
II. Background
Wireless communication systems are widely deployed to provide various communication content such as voice, video, packet data, messaging, broadcast, etc. These wireless systems may be multiple-access systems capable of supporting multiple users by sharing the available system resources. Examples of such multiple-access systems include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal FDMA (OFDMA) systems, and Single-Carrier FDMA (SC-FDMA) systems.
A wireless communication system may include any number of base stations that can support communication for any number of subscriber stations. A subscriber station may communicate with a base station via the downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the subscriber station, and the uplink (or reverse link) refers to the communication link from the subscriber station to the base station.
The system may support hybrid automatic retransmission (HARQ). For data transmission on the downlink with HARQ, a base station may send a transmission for a packet to a subscriber station. The subscriber station may decode the packet based on the transmission and may send an acknowledgement (ACK) if the packet is decoded  correctly or a negative acknowledgement (NAK) if the packet is decoded in error. The base station may send another transmission for the packet if a NAK is received and may terminate transmission of the packet if an ACK is received. The ACK/NAK feedback is useful but consumes resources on the uplink. It is thus desirable to send ACK/NAK feedback as efficiently as possible.